Person: Sánchez Salvador, José Luis
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First Name
José Luis
Last Name
Sánchez Salvador
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Identifiers
19 results
Search Results
Now showing 1 - 10 of 19
Item In Situ Production and Application of Cellulose Nanofibers to Improve Recycled Paper Production(Molecules, 2019) Balea Martín, Ana; Sánchez Salvador, José Luis; Monte, María de la Concepción; Merayo Cuevas, Noemí; Negro Álvarez, Carlos Manuel; Blanco Suárez, ÁngelesThe recycled paper and board industry needs to improve the quality of their products to meet customer demands. The refining process and strength additives are commonly used to increase mechanical properties. Interfiber bonding can also be improved using cellulose nanofibers (CNF). A circular economy approach in the industrial implementation of CNF can be addressed through the in situ production of CNF using side cellulose streams of the process as raw material, avoiding transportation costs and reducing industrial wastes. Furthermore, CNF fit for use can be produced for specific industrial applications.This study evaluates the feasibility of using two types of recycled fibers, simulating the broke streams of two paper machines producing newsprint and liner for cartonboard, to produce in situ CNF for direct application on the original pulps, old newsprint (ONP), and old corrugated container (OCC), and to reinforce the final products. The CNF were obtained by 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-mediated oxidation and homogenization at 600 bar. Handsheets were prepared with disintegrated recycled pulp and different amounts of CNF using a conventional three-component retention system. Results show that 3 wt.% of CNF produced with 10 mmol of NaClO per gram of dry pulp improve tensile index of ONP ~30%. For OCC, the same treatment and CNF dose increase tensile index above 60%. In both cases, CNF cause a deterioration of drainage, but this effect is effectively counteracted by optimising the retention system.Item Optimization of reagent consumption in TEMPO-mediated oxidation of Eucalyptus cellulose to obtain cellulose nanofibers(Cellulose, 2022) Xu, Hongyu; Sánchez Salvador, José Luis; Balea Martín, Ana; Blanco Suárez, Ángeles; Negro Álvarez, Carlos ManuelEucalyptus cellulose is usually pre-treated by oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), NaBr and NaClO at pH 10.5 and 25 °C before the mechanical process required to obtain cellulose nanofibers (CNFs). In this study, different aspects to improve the effectiveness and sustainability of the TEMPO-mediated oxidation are analyzed. The optimization was carried out at different reaction times by modifying both the concentration of the NaClO and the amount of the catalysts (TEMPO and NaBr). Results show that the carboxyl groups increased up to 1.1 mmol/g with 5 mmol NaClO/g after 50 min, and that the catalyst concentration can be reduced to 0.025 mmol TEMPO/g and 0.5 mmol NaBr/g to minimize costs while maintaining the high fibrillation degree of the CNFs. The kinetic of the reaction can be considered as zero-order with respect to NaClO, and as first order with respect to cellulose. As a result of this work, the catalyst doses are reduced up to 75% compared to the most widely used catalyst doses (0.1 mmol/g TEMPO and 1 mmol/g NaBr), obtaining highly fibrillated CNFs with a lower environmental impact. This reduction of catalyst doses will reduce the costs and facilitate the implementation of CNF production at industrial scale.Item Comparison Of Mechanical And Chemical Nanocellulose As Additives To Reinforce Recycled Cardboard(Scientific Reports, 2020) Sánchez Salvador, José Luis; Balea Martín, Ana; Monte Lara, M. Concepción; Negro Álvarez, Carlos Manuel; Miller, Meaghan; Olson, James; Blanco Suárez, ÁngelesRecycling cycles cause a decrease in mechanical paper properties due to cellulose fiber degradation. The use of cellulose micro/nanofibers (CMF/CNF) to reinforce paper strength has been well studied, although it has been found to have negative effects on drainage. However, the application of CMF/CNF as paper reinforcement is affected by the nanocellulose type. Thus in this study mechanical and chemical treatments in CNF production were compared. Old corrugated container (OCC) pulp used to produce recycled cartonboard was reinforced with 1) CMF from never-dried northern bleached softwood kraft pulp (NBSK) highly refined in a 16-inch low consistency refiner at 1200 rpm and 25 kW of net power; and 2) CNF from NBSK pulp treated by TEMPO-mediated oxidation and homogenization at 600 bars. CMF/CNF and OCC were pulped at the same time and handsheets formed with cationic starch (CS) as retention system. Mechanical, drainage and flocculation properties were evaluated and compared. Data were also compared with other sources of TEMPO CNF. Results show an improvement in mechanical properties, drainage and flocculation when OCC is reinforced with CMF obtained with LCR. Therefore, high fibrillation was not necessary to improve mechanical paper or cardboard properties.Item Micro- and Nanofibrillated Cellulose from Annual Plant-Sourced Fibers: Comparison between Enzymatic Hydrolysis and Mechanical Refining(Nanomaterials, 2022) Aguado, Roberto; Tarrés, Quim; Pèlach, Maria Àngels; Mutjé, Pere; Fuente González, Elena de la; Sánchez Salvador, José Luis; Negro Álvarez, Carlos Manuel; Delgado Aguilar, MarcThe current trends in micro-/nanofibers offer a new and unmissable chance for the recovery of cellulose from non-woody crops. This work assesses a technically feasible approach for the production of micro- and nanofibrillated cellulose (MNFC) from jute, sisal and hemp, involving refining and enzymatic hydrolysis as pretreatments. Regarding the latter, only slight enhancements of nanofibrillation, transparency and specific surface area were recorded when increasing the dose of endoglucanases from 80 to 240 mg/kg. This supports the idea that highly ordered cellulose structures near the fiber wall are resistant to hydrolysis and hinder the diffusion of glucanases. Mechanical MNFC displayed the highest aspect ratio, up to 228 for hemp. Increasing the number of homogenization cycles increased the apparent viscosity in most cases, up to 0.14 Pa·s at 100 s−1 (1 wt.% consistency). A shear-thinning behavior, more marked for MNFC from jute and sisal, was evidenced in all cases. We conclude that, since both the raw material and the pretreatment play a major role, the unique characteristics of non-woody MNFC, either mechanical or enzymatically pretreated (low dose), make it worth considering for large-scale processes.- Project number: 242
Item Estrategias para favorecer la comunicación Universidad-Empresa y fomentar la inserción laboral de los estudiantes a lo largo de su trayectoria formativa(2023) Fuente González, Elena De La; Alache Manchado, Beatriz; Ayllon Salazar, Joaquin; Balea Martín, Ana; Barrientos Báez, Almudena Carmen; Blanco Suárez, María Ángeles; Comin Barrio, Jorge; Corpa Garcia, Elena; Corpa Santos, Cristina; Dieguez Molina, Xena Teresa; Finkel Morgenstern, Lucila; Gallego Ferrández, Alicia; Gómez Sierra, María Eugenia; Martín Hernández, Mª Isabel; Martínez Lezon, Leila; Monte Lara, María Concepción; Negro Álvarez, Carlos Manuel; Ojembarrena Jiménez, Francisco De Borja; Parra Contreras, María Pilar; Sánchez Salvador, José Luis; Sanz González, Javier; Souto Casas, Alberto; Tijero Cruz, Antonio; Valdés Antón, Pablo; Vergara Ortega, Sandra; Xu, Hongyu Item Enhanced Morphological Characterization of Cellulose Nano/Microfibers through Image Skeleton Analysis(Nanomaterials, 2021) Sánchez Salvador, José Luis; Campano Tiedra, Cristina; López Expósito, Patricio; Tarrés, Quim; Mutjé, Pere; Delgado Aguilar, Marc; Monte Lara, M. Concepción; Blanco Suárez, ÁngelesThe present paper proposes a novel approach for the morphological characterization of cellulose nano and microfibers suspensions (CMF/CNFs) based on the analysis of eroded CMF/CNF microscopy images. This approach offers a detailed morphological characterization and quantification of the micro and nanofibers networks present in the product, which allows the mode of fibrillation associated to the different CMF/CNF extraction conditions to be discerned. This information is needed to control CMF/CNF quality during industrial production. Five cellulose raw materials, from wood and non-wood sources, were subjected to mechanical, enzymatic, and (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO)-mediated oxidative pre-treatments followed by different homogenization sequences to obtain products of different morphologies. Skeleton analysis of microscopy images provided in-depth morphological information of CMF/CNFs that, complemented with aspect ratio information, estimated from gel point data, allowed the quantification of: (i) fibers peeling after mechanical pretreatment; (ii) fibers shortening induced by enzymes, and (iii) CMF/CNF entanglement from TEMPO-mediated oxidation. Being mostly based on optical microscopy and image analysis, the present method is easy to implement at industrial scale as a tool to monitor and control CMF/CNF quality and homogeneity.Item Simplification of gel point characterization of cellulose nano and microfiber suspensions(Cellulose, 2021) Sánchez Salvador, José Luis; Monte Lara, M. Concepción; Negro Álvarez, Carlos Manuel; Batchelor, Warren; Garnier, Gil; Blanco Suárez, ÁngelesNanocellulose is an emerging material that needs to be well characterized to control its performance during industrial applications. Gel point (Øg) is a convenient parameter commonly used to estimate the aspect ratio (AR) of cellulose nano/microfibers (CNFs/CMFs), providing critical information on the nanofiber network. However, its estimation requires many sedimentation experiments, tedious and time consuming. In this study, a simpler and faster technique is presented to estimate Øg, based on one or two sedimentation experiments, reducing the experiments by a factor of at least 2.5. Here, this new methodology is successfully validated by using the Øg of different CNF/CMF hydrogels calculated with the traditional methodology, showing an error lower than 7%. The error in the estimation of the AR is lower than 3% in all cases. Furthermore, the two mathematical models currently used to estimate Øg, the smoothing spline and the quadratic fit, are compared and the mathematical assumptions improved.Item Critical comparison of the properties of cellulose nanofibers produced from softwood and hardwood through enzymatic, chemical and mechanical processes(International Journal of Biological Macromolecules, 2022) Sánchez Salvador, José Luis; Campano Tiedra, Cristina; Balea Martín, Ana; Tarrés, Quim; Delgado Aguilar, Marc; Mutjé, Pere; Blanco Suárez, Ángeles; Negro Álvarez, Carlos ManuelCurrent knowledge on the properties of different types of cellulose nanofibers (CNFs) is fragmented. Properties variation is very extensive, depending on raw materials, effectiveness of the treatments to extract the cellulose fraction from the lignocellulosic biomass, pretreatments to facilitate cellulose fibrillation and final mechanical process to separate the microfibrils. Literature offers multiple parameters to characterize the CNFs prepared by different routes. However, there is a lack of an extensive guide to compare the CNFs. In this study, we perform a critical comparison of rheological, compositional, and morphological features of CNFs, produced from the most representative types of woody plants, hardwood and softwood, using different types and intensities of pretreatments, including enzymatic, chemical and mechanical ones, and varying the severity of mechanical treatment focusing on the relationship between macroscopic and microscopic parameters. This structured information will be exceedingly useful to select the most appropriate CNF for a certain application based on the most relevant parameters in each case.- Project number: 290
Item Desarrollo y aplicación de una metodología innovadora para realizar visitas técnicas virtuales a empresas y centros de investigación() Blanco Suárez, Ángeles; Balea Martín, Ana; Monte Lara, M. Concepción; Negro Álvarez, Carlos; de la Fuente González, Elena; Hierro Paredes, Eva; Romero De Ávila Hidalgo, María Dolores; Tijero Cruz, Antonio; Plaza Rodriguez, Jesus; Sánchez Salvador, José Luis; Ojembarrena Jiménez, Francisco de Borja; Xu, Hongyu; Gascó Guerrero, Antonio María; Márquez Negro, Alejandro; Hermosilla Redondo, Daphne; Aguado García, Sofía; Alarcón Mondéjar, Juan Ignacio; González Seade, Sofía; Sánchez Calatayud, TaniaEl objetivo del proyecto es desarrollar una metodología innovadora para realizar visitas técnicas virtuales a plantas industriales y/o centros de investigación con alumnos que podrán utilizarse en 8 asignaturas de 4 grados y 2 másteres de la UCM. Item Valorization of Vegetable Waste from Leek, Lettuce, and Artichoke to Produce Highly Concentrated Lignocellulose Micro- and Nanofibril Suspensions(Nanomaterials, 2022) Sánchez Salvador, José Luis; Marques, Mariana ; Brito, Margarida ; Negro Álvarez, Carlos Manuel; Monte, Maria Concepcion; Manrique, Yaidelin ; Santos, Ricardo ; Blanco Suárez, María ÁngelesVegetable supply in the world is more than double than vegetable intake, which supposes a significant waste of vegetables, in addition to the agricultural residues produced. As sensitive food products, the reasons for this waste vary from the use of only a part of the vegetable due to its different properties to the product appearance and market image. An alternative high-added-value application for these wastes rich in cellulose could be the reduction in size to produce lignocellulose microand nanofibrils (LCMNF). In this sense, a direct treatment of greengrocery waste (leek, lettuce, and artichoke) to produce LCMNFs without the extraction of cellulose has been studied, obtaining highly concentrated suspensions, without using chemicals. After drying the wastes, these suspensions were produced by milling and blending at high shear followed by several passes in the high-pressure homogenizer (up to six passes). The presence of more extractives and shorter fiber lengths allowed the obtention of 5–5.5% leek LCMNF suspensions and 3.5–4% lettuce LCMNF suspensions, whereas for artichoke, only suspensions of under 1% were obtained. The main novelty of the work was the obtention of a high concentration of micro- and nanofiber suspension from the total waste without any pretreatment. These high concentrations are not obtained from other raw materials (wood or annual plants) due to the clogging of the homogenizer, requiring the dilution of the sample up to 1% or the use of chemical pretreatments.